Question about RTO Takagi TM-1-N Mobius Tankless Water Heater - Natural Gas

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Hello, i have a Takagi T-K3 i am getting a code error 991. It had been operating flawlessly for about 4 months now when i turn it on nothing happens at all i have checked and cleaned my sensors. checked air intake and exhaust i did make some minor changes to the exhaust (added a condensate trap). I still try to start it but nothing happens i still get the 991 error code. Is there a way to reset this code or does it go away once the problem is fixed. Thank you Mike

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  • electro354 Mar 26, 2011

    yeah i tried customer support but they are not open on weekends quess its no showers this weekend. Seems dumb not to put it in the manual i have the manual but like you said no dice on the reset code.

  • electro354 Mar 28, 2011

    We also had some pretty good winds. could that have given me my 991 code?


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Ok please go to the above website it addresses your issue directly.
above & below, is your manual. below has about 991.

Briefly it may have to do with the sparker ignition... please read above...

Posted on Mar 30, 2011

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Not sure if you have the manual for that so here it is.....

It however does not mention how to reset that reset it I know that you need to push a specific set of buttons on a specific order...i do not know what they are or the order...

They are supposed to have full time customer support... here is the page for the will have to call them for the reset code as it is not public knowledge...


Posted on Mar 26, 2011

  • D. Floyd Kolb
    D. Floyd Kolb Mar 26, 2011

    You get no argument from me on that!!! There is no reason why they cannot place the sequence of buttons in the manual...
    I have installed a few of these units but have never had to get the code from them...
    Would love to try and call them sometime but just have not taken the time to do it...


  • D. Floyd Kolb
    D. Floyd Kolb Mar 28, 2011

    Yes... the 991 code is a poor combustion code...

    high winds could definetely cause that to occur...


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